Improvement in caps for lamp-globes



H. H. HULBURT. Gap for Lamp-Globes;

No. 222,189. Patented D.ec. 2,1879.

mfnqsses Ina calm ILPETERS. FNOTO-LITHOGRAFMER, WASHINGTON. n c,

U TTED STATES PATENT OFFICE.

HENRY H. HULBURT, OF PHILADELPHIA, PENNSYLVANIA.

IMPVROVEMENT IN CAPS FOR LAMP-GLOBE-Sfl Specification forming part ofLetters Patent No. 222,189, dated December 2, 1879; application filedJuly 31, 1879.

To all whom it may concern:

' Beit known that I, HENRY H. HULBURT,

of Philadelphia,in the county of Philadelphia and Stateoil-Pennsylvania, have invented a new and useful Improvement in Tops forPetroleum Lamp-Globes, which improvement is and accompanying drawings. UMy invention relatesto certain newand useful nnprovementsin the class ofmetallic caps fully set forth 'in the following specification I forglass globes designed to be used in place of chimneys onpetroleum-lamps; and the invention consists in a novel construction ofcap and means for securing it to globes having difl'erent-sized openingsat' the top, all as will be hereinafter fully described, andspecifically pointed out in the claim.

, Referring to the accompanying drawings, in which similar letters ofreference indicate like parts, Figure 1 represents an exterior view ofthe slotted cap; Fig. 2, aninterior view of the same, showing thespiral-spring attachment by which said cap is secured onv top of theglobe. Fig. 3 is a sectional view of a petroleu'm lamp-burner with aglobe and my imp edge of the globe, or to extend over a short distance,as shown in Fig. 3.

O.-represents 'a spiral spring, secured on the under side and near theouter edge of said cap,

for the purpose of securing the cap on the globe, it being sprung insideof the globe, as clearly shown in Fig. 3.

The advantage of the spiralspring as a fastener is that the same cap maybe used on globes having different-sized openings at the top, the springadjusting itself to anyslightdifference in the diameter of the globe,and at the same time avoiding all breaking caused by expansion andcontraction of the globe.

As the slotted cap has noopenin g in the center immediately over'theflame, the heated air inside the globe is obstructed in its directoutward passage, reflected back and forced through the slots or openingsB, n'ear the edge of the cap, (these being the only openings,) and bythis means the flickering and unsteadiness of the flame, caused by anyslight disturbance in the outside atmosphere, is completely overcome,and the light under ordinary circumstances is much more brilliant andsteady than in globes and chimneys having the draft directly over theflame of the lamp.

I am aware that a metallic disksecured by spring-standards over the topof a globe as a substitute for lampchimneys, also a, perforated cap fora similar purpose, and also spiral springs for securing lamp-chimneys inposition are old, and such I do not wish to be understood as claiming,broadly, as my invention; but 1 What I claim as my invention is- Theherein-described metallic capfor the globes of petroleum-lamps, having aseries of elongated slots or openings, B, near itsouter edge, a flange,D, adapted tofit closely over the top of the globe, and a spiralspring,G, secured to the under side near the-outer edge of the cap, and adaptedto fit inside of globes having different-sized openings at the top forsecuring the cap thereto, substantially as and for the purposespecified. v p i v HENRY H. HULBURT. Witnesses:

S. S. Downs, HENRY CLAY.

